The gorramn book turned up on September 15th -- as my subject says, four months and three days after it was postmarked.
It was indeed sent by airmail. The address was legible enough for that not to be a reason for it to have gone missing. I'm baffled. I've never had airmail from the UK take this long before!
I emailed the seller and apologised for name-calling on eBay, and he emailed me back to apologise for calling me useless. We would've withdrawn our feedback but it's over thirty days since we left it and eBay says we can't. Despite the capslocking and such, he turned out to be pretty decent. I guess that's fair enough, since it genuinely wasn't his fault the book took so long to show up (and genuinely wasn't my fault that I assumed he'd gypped me).
*sigh* Anyone want a copy of Robin Jarvis's The Final Reckoning, now I have two?